Domestic appliance



Nov. 21, 1961 Filed Sept. 23, 1957 T. F. ZUREK DOMESTIC APPLIANCE 2Sheets-Sheet l INVENTOR.

THOMAS F. ZUREK QiLJ/W ATTORNEY Nov. 21, 1961 T. F. ZUREK 73,009,470

DOMESTIC APPLIANCE Filed Sept. 25, 1957 2 Sheets-Sheet 2 INVENTOR.THOMAS F. ZUREK iiM/AM ATTORN EY United States Patent Ofitice 3,009,470Patented Nov. 21, 1961 3,009,470 DQMESTKC APPLIANCE Thomas F. Zurek,Chicago, 111., assignor to General Electric Company, a corporation ofNew York Filed Sept. 23, 1957, Ser. No. 685,447 7 Claims. (Cl. 134176)This invention relates to dishwashing apparatus, and, in particular, toan improved means for rotatably mounting a reaction spray device forreceipt of a continuous supply of liquid under pressure.

Dishwashers designed especially for domestic use, employ a lower and anupper rack for suitably supporting the dishes and other articles to bewashed. It was been found that improved washability results from theemployment of two rotating liquid distribution devices, one of which isdisposed below the lower rack and the other is arranged intermediate thelower and upper rao'k. By having the lower liquid distributorconstructed as a reaction spray device, pursuant to which the reactionof jets issuing from extended arms of the device induce rotation, a veryefi'icient Washing action can be obtained. In a form of dishwasherembodying the present invention and manufactured commercially by myassignee herein, the intermediate liquid distributor is automaticallymechanically coupled to the lower reaction spray device, whereby it ismechanically rotated by said lower device and, in addition, receives itssupply of liquid therefrom. The lower reaction spray device receives acontinuous supply of liquid under moderate pressurefor example,approximately eleven pounds per square inchfrom a motor-driven pumpwhich circulates liquid from the dishwasher tub to the conduit supplyingthe lower reaction spray device.

Domestic dishwashers are sometimes quite carelessly loaded. In spite ofprecautions taken in the design of the racks, it is possible so to loadthe racks that a plate or a cooking utensil may project into the path ofrotation of the liquid distribution devices. In the said commercial formof dishwasher embodying the present invention, the intermediate liquiddistributor is of a flat disk-like construction and is constructed of arelatively light-weight plastic material which has a somewhat yieldingsurface. Tests have shown that it is not possible to damage even anarticle of delicate china which may accidentally come into contact withthe intermediate distributor. It is most advantageous, however, to makethe lower distributor or reaction spray device entirely of metal inorder to provide an adequate hub portion from which extend therelatively long tubular arms through which the liquid flows and issuesinto the tub through the variously disposed apertures. In order tominimize the possibility of damage if one of the tubular members shouldstrike an article of china or the like, the lower reaction spray deviceis made as light in weight as it is practicable to do, and, in addition,the reaction jets are arranged so that there is actually a very lowrotational torque produced thereby. In such an arrangement, there is notenough rotational effort or momentum present in the lowermost device todamage any article which may be in its path of rotation. This lightnessand low torque characteristic introduced serious sealing problems at thejuncture of the stationary supply conduit and the rotating hub. Evenlight weight seals of the so-called face type interposed substantialfrictional resistance and, in addition, were subject to irregular wear,for during its operation the reaction spray device is per mitted andwill experience some gyration about itsvertical axis in view of theturbulent conditions existing within the tub during the operation of thedishwasher.v

The present inventiondispenses with a seal between the hub and thestationary supply conduit. Instead, the

upper end wallof the conduitis machined soiasto be t plane and normal tothe vertical axis, whereas the lower portion of the hub is beveled so asto provide an edge from which the wall of the hub extends upwardly andoutwardly. The hub is mounted upon a pivot bearing which extendsupwardly from the conduit into cooperative relation with a bearingprovided in the hub, and the respective bearing elements are sized anddisposed so that there is a minute clearance between the edge of the huband the facing surface of the conduit. The bearing elements are furtherarranged so that under maximum deflection of the hub during itsrotation, there will be no contact of the edge of the hub with thesurface of the conduit. A further characteristic of the hub and conduitis that the inside wall of the hub is slightly larger in diameter thanthe inside wall of the conduit, whereby the edge defining the bottom ofthe hub is disposed intermediate the inner and outer Walls of theconduit. The effect of this arrangement is that heavier than water foodsoil, such as coffee grounds, which may have escaped the screened inletof the circulation pump and thus pass into the hub, will be carried bymomentum past the small gap between the hub and the conduit; whereasfood soil which is of equal or less specific gravity than water will becarried through the gap between the hub and the conduit. The sharp edgeof the hub forms a weir over which the liquid passes with substantialforce. The disposition of the edge radially outwardly of the inner wallof the conduit provides sufficient turbulence to continually purge orscour the junction between the hub and the conduit, therefore preventingaccumulations of food soil therebetween.

It is, therefore, a principal object of the present invention to providea low-friction and substantially clog-proof means for rotatably mountinga reaction spray device on a conduit supplying the device with liquidunder pressure.

It is another object of the invention to provide a reaction spray deviceand a supply conduit therefor, arranged to minimize the loss of liquidat the junction therebetween without employing mechanical sealingstructures.

It is a further object of the invention to provide a mounting means fora reaction spray device which, although securely maintained againstaxial displacement with respect to a liquid supply conduit, will operatewith minimum friction and escape of liquid.

Other features and advantages will be apparent from the followingdetailed description of a presently preferred embodiment of theinvention, read in connection with the accompanying drawings in which:

FIG. 1 is a fragmentary front elevational view, partly in section, 'of adishwashing apparatus embodying the present invention;

FIG. 2 is a fragmentary sectional elevation showing the preferredrelationship between the reaction spray device and the supply conduitwith the apparatus idle;

FIG. 3 is a view similar to FIGURE 2 but showing the relationship of theelements when the dishwasher is in operation;

FIG. 4 is an enlarged representation of the circled portion of FIG. 3 toschematically show the water action; and

FIG. 5 is a fragmentary elevational view of'the upper liquiddistributor.

FIG. 1 shows in fragmentary front elevational section a dishwasher 1embodying the present invention. The dishwasher comprises a cabinet 2housing a tub 3 equipped with upper and lower-trackways 4 and 5 whichslidably. accommodate the upper and lower racks 6 and 7. It will beunderstood-that the cabinet is provided with a.

door (not-shown) which is hinged for movement between a substantiallyvertical closed position and a substantially horizontal openposition.When the door'is in its open positiornthe respective racks may bedrawnforwardly Q with the dishes and other articles (not shown) which are tobe washed.

The distribution of the washing liquid throughout the interior of thetub is accomplished by means of an upper liquid distributor 8 which isrotatably supported on a standard 9 fixed to the lower rack 7 so as tobe intermediate the upper and lower racks, and a lower distributor 30,later described in detail. The water distribution device S is suppliedwith washing liquid through the tube 10 which about its lower portionhas a support hub 11 of nylon or similar plastic material, shaped (seeFIG. 2) to center within opening in the central portion of the lowerrack 7. The tube It) terminates in a bell-shaped connection 12 throughwhich the washing liquid enters said tube, as later described.

Heated water is introduced into the tub by way of a solenoid valve 13,the inlet 14 of which is connected to a suitable source of heated water,such as the hot water supply of the building. The discharge tube 15 fromvalve 13 is arranged to discharge into an inlet fixture 16 whichcommunicates with the tub 3 through the port 17. During washing andrinsing operations, the liquid in the tub is continuously circulated bymeans of the centrifugal pump 18, driven by motor 19. Pump 18 connectswith the tub by way of the inlet fitting 20. The inlet fitting is, ofcourse, equipped with a suitable filter or strainer (not shown) toprevent as much as possible the recirculation of food soil particleswhich have been removed from the dishes and other articles during thewashing operation. As a practical matter, of course, it is virtuallyimpossible to make the filtering device completely effective and somesmall articles of soil, such as coffee grounds, fragments of cereals,and very small bits of leafyvegetables may find their way through thefiltering device and will be redischarged into the tub. The outlet ofthe pump 18 communicates by way of the fittings 21 and 22 with avertical, rigid conduit 23. A pump 25, driven by a suitable electricmotor 26, is employed for the discharge of the spent washing or rinsingliquid. The discharge pump communicates with the tub by way of asuitable drainage fitting 27 and discharges through a pipe 23 to a pointof connection with the drainage or plumbing waste piping (not shown) ofthe building.

It will be understood that the operation of the fill-valve 13 and therespective circulation and drainage pumps 18 and 25 are usually underthe control of an automatic timing device (not shown), as is nowwell-known in the art. The precise time-cycle and the method of controlthereof form no part of the present invention, and, therefore, they havebeen omitted from the present description.

The lower liquid distribution device which embodies the presentinvention is disposed for rotation relative to the conduit 23. As bestappears in FIG. 1, the device 30 comprises a hub 31 from which extendthe tubular arms or conduits 32. The arms are plugged at theirrespective ends, and are provided with orifices 33 and 34 which operateto direct fan-like sprays or jets of liquid throughout the lower portionof the tub, thereby providing the washing operation for the articles inthe lower rack. Certain of the jets-for example, the jets issuing fromorifices 34are arranged so as to provide reaction forces which cause thedistribution device 30 to rotate. At a pressure of about eleven poundsgage per square inch which the pump 18 supplies to the device 30, thereaction jets will effect a rotation at a speed of approximately 60 rpm.The liquid distribution device 30 is very light in weight. -In thepresent commercial form, the total weight of the lower distributiondevice is .54 pound, with approximately 60% thereof represented by thehub 31. This light weight, coupled with the relatively slow speed ofrotation so reduces the momentum or rotative effort of the device 30during its' operation thatthere is no possibility of damage to anyarticle which may project from the lower rack 7 into the path of one ofthe rotating arms. As previously noted, the low forces of rotationintroduced substantial problems as respects the mounting of the device30 on the conduit 23. No available sealing device was found which wouldnot interpose substantial resistance to rotation; and none was foundwhich was not vulnerable to being clogged by the minute particles offood soil which may be entrained in the washing or rinsing liquid.

There are presently-known reaction spray devices which rotate freely ona liquid supply pipe and are devoid of scaled joints between the pipeand the device. Such prior-art devices, however, are characterized bysubstantial mass, relatively wide facing surfaces between the hub of thedevice and the supply pipe, and freedom to rise axially under thepressure of liquid being supplied thereto. In these devices, there is asubstantial escape of liquid, which, of course, is non-productive asrespects any washing effect. The present invention eliminates completelyany sealing device and yet provides construction which reduces theescape of liquid to a minimum and precludes any possibility of jammingor clogging.

As best shown in FIG. 2, the conduit 23 is provided with a spider 35which supports a pivot bearing 36. The bearing 36 is screw-threadedlyaffixed to the spider 35, and in order to obtain the desired verticalclearance between the hub 31 and the conduit 23, it is contemplated thatshims 37 may be interposed between the bearing 36 and the spider 35. Thebearing 36 has a conical end 38 and an enlarged shoulder 40. The hub 31is formed with a socket 41 which comprises the central portion of anintegral hub construction. The socket 41 has a conical seat 42 whichrests upon the conical end 38 of the hearing 36.

It will be noted that the open upper end of conduit 23 is formed with aplane surface 43 which is precisely normal to the axis of the pivotbearing 36; and in this connection it will be understood that saidbearing 36 and the socket 41 are coaxial with respect to their mainstructures. The lower rim 44 of the hub 31 is beveled at substantially a45 degree angle to form a wall which extends upwardly and outwardly fromthe edge 45. Preferably, the edge is sharp; at least it should be ofmuch less radial width that that of the wall of the conduit 23. Also,the inner wall of the hub at the edge should be radially outward of theinner Wall of the conduit, and I prefer the edge to be spaced outwardlyabout one'quarter of the thickness of the conduit wall. It is a featureof the construction that the edge 45 is spaced above the wall 43 aminute amount. In the commercial embodiment of the invention, thespacing is of the order of .015 inch. It will be understood that theshim or shims 37 will establish said spacing within relatively closelimits. During the operation of the lower water distribution device 30,the very turbulent conditions within the dishwasher tub make itliterally impossible for the device 30 to rotate in a preciselyhorizontal plane. However, it is considered important that the edge 45not touch the surface 43 and, therefore, the socket 41 is arrangedrelative to the pivot 36 so that the inner wall of the socket willcontact the external wall of the shoulder 40 before the hub 31 hastilted sufiiciently from the vertical to bring the edge 45 into contactwith the facing surface 43 of the conduit. In practice, the relationshipof the hub 41 to the shoulder 40 is such that the hub of the device 30is permitted only about a one degree incline from the vertical. Thisinclination will not permit the edge 45 to touch the conduit or comewithin the inner area of the conduit.

In contrast to the previously described reaction spray devices which arearranged so that the device may rise or move axially with respect to theconduit, the present invention is adapted to arrangements in which theaxial separation of the hub 31 from the conduit 23 is precluded. Asshown in FIGS. 2 and 3, the upper end 46 of the hub 31 is open and thereis a fiexiblecoupling 47 secured about said open end. The coupling 47has an opening 48 which is substantially less in diameter than theopening 46 and the coupling 47 is disposed immediately beneath the bellportion 12 of the conduit supplying the upper rotor 8. When liquid underpressure enters the lower distributor 30, a substantial portion of itpasses through the hub 31 and impinges upon the overhanging wall portionof the coupling 47. This expands the coupling upwardly, as shown in FIG.3, and the coupling exerts a substantial pressure against the bottom ofthe bell 12; in fact, the pressure is such as to raise the conduit 10relative to the lower rack 7, as clearly indicated in FIG. 3. It will benoted from FIG. 5, that the upper distributor 8 is rotatably engagedwith the supporting structure 9 by means of a pivot bearing 48 and asocket 50. There is sufiicient vertical latitude in the bearing andsocket relationship to permit the conduit 10 to be lifted beforeencountering the resistance of the supporting structure 9. Nevertheless,the downward component of forces exerted against the hub 31 maintainsthe base 42 of the socket 41 firmly on the conical end 38 of the bearing36. Even under severe operating conditions, therefore, there is noseparation of the edge 45 relative to the surface 43 beyond the spacingwhich is originally provided.

FIG. 4 illustrates somewhat schematically the liquid action at thejuncture of the hub 31 and the conduit 23. Because of the very smallclearance between these elements, only a minute portion of theliquidwhich is circulating at a rate of 30 gallons per minutecan findits way through the gap. The edge 45 constitutes a sharp weir over whichthe water escapes with substantial velocity and the location of saidedge relative to the inner Wall of the conduit 23 results in aturbulence which continuously scours the adjacent wall areas andprevents the accumulation of food soil thereon. As soon as the liquidand any entrained particles of food soil carried thereby get beyond theedge 45, the outward and upward flare of the wall 44 insures that thefood soil will escape from between the facing wall portions. It has beenobserved that only food soil which is equal to or lighter than waterpasses through the gap. Particles which are heavier than water, as forexample, the illustrated coffe ground G, will project by their ownmomentum beyond the gap and, therefore, cannot lodge within or in frontof the gap. This path of movement of the heavier than water solids is,of course, considerably aided by the fact that no part of the edge willcome Within the conduit 23 even at maximum deflection of the hub 31.Ordinarily, the spacing of the edge 45 is outwardly of the inside wallof the conduit 23, with the result that there is a very abrupt cornerwhich the heavier solids cannot negotiate.

Pursuant to the present invention, therefore, there is provided arotatable connection between a reaction spray device and a supplyconduit, in which a small, predetermined, gap is maintained at alltimes, minimizing friction and loss of liquid. Gelatinous or adhesivesoil which may be in suspension in the liquid will not accumulate in thegap, nor will said particles come to rest therein.

While there has been described What is at present considered to be thepreferred embodiment of the invention, it will be understood thatvarious modifications may be made therein, and it is intended to coverin the appended claims all such modifications as fall within the scopeof the invention.

I claim:

1. For use in dishwashing apparatus having a tub to receive articles tobe Washed, means for supplying said tub with a quantity of washingliquid, and pump means to draw said liquid from said tub and return itthereto under moderate pressure: the improvement in apparatus fordistributing said liquid among the articles in said tub, comprising aconduit adapted to be fixed Within said tub to receive liquid from saidpump, said conduit having an open-ended vertical portion, a waterdistribution hub member rotatably mounted on said conduit verticalportion to receive liquid directly therefrom, the end wall of said hubfacing said conduit being beveled in an upward and outward direction toprovide an uninterrupted sharp edge radially outward of the inner wallof said conduit portion, and pivot bearing means interposed between saidconduit and said hub for coaxially mounting said hub in predeterminedvertical space relation to the discharge end of said conduit whilepermitting limited gyration of said hub about the axis of rotation; thediameter and spacing of said hub edge relative to said conduit end wallbeing such that at maximum gyration of said hub there remains a verticalclearance between said edge and said end Wall and no part of said edgeis within the area defined by the inner wall of said conduit.

2. For use in dishwashing apparatus having a tub to receive articles tobe washed, means for supplying said tub with a quantity of Washingliquid, and pump means to draw said liquid from said tub and return itthereto under moderate pressure: the improvement in apparatus fordistributing said liquid among the articles in said tub, comprising aconduit adapted to be fixed within said tub to receive liquid from saidpump, said conduit having an open-ended vertical portion, a waterdistribution hub member rotatably mounted on said conduit verticalportion to receive liquid directly therefrom, the end wall of said hubfacing said conduit being leveled in an upward and outward direction toprovide an uninterrupted sharp edge radially outward of the inner wallof said conduit portion, pivot bearing means interposed between saidconduit and said hub for coaxially mounting said hub .With the edgethereof in predetermined vertical space re lation to the discharge endof said conduit, means for effecting rotation of said hub upon flow ofliquid thereinto, and means carried by said hub independent of saidpivot bearing means for maintaining said spaced relationship duringrotation of said hub.

3. The improvement in liquid distribution apparatus according to claim2, in which the spacing between the bottom edge of the hub and the endwall of said conduit during rotation of said hub is of the order of0.015".

4. In a dishwasher having a tub, and a rack removab'ly contained thereinfor receiving the articles to be washed, a rigid, open-ended conduitextending into said tub from a wall thereof, and means for supplyingsaid conduit with liquid under pressure for discharge into said tub: theimprovement comprising a liquid distribution device having a hub portionopenly facing said conduit to receive liquid therefrom and tubularmembers communcating with said hub and extending therefrom, means forfreely rotatably mounting said hub portion on said conduit intermediatesaid conduit and said rack, said means comprising a hearing membersecured to and extending axially from said conduit, a bearing membersecured to and axially disposed relative to said hub portion, the saidbearing members being in interfitting relation and disposing said hubportion in spaced relation to the adjacent end wall surface of saidconduit, and resilient means extending from said hub portion andengageable with structure carried by said rack only upon flow of liquidinto said hub portion to maintain said. hub and said conduit in the saidspacial relationship at all times during flow of liquid into said hubportion.

5. In a dishwasher having a tub and rack means removably containedtherein for receiving articles to be washed, a rigid, open-ended conduitextending into said tub intermediate said rack and a wall of said tub,and means for supplying said conduit with liquid under pressure fordischarge into said tub: the improvement comprising a liquiddistribution device having a hub portion openly facing said conduit toreceive liquid therefrom and apertured tubular members communicatingwith said hub' and extending therefrom, means for freely rotatablymounting said hub portion on said conduit intermediate said conduit andsaid rack, said means comprising a hearconduit, a bearing member securedto and axially disposed relative to said hub portion, the said bearingmembers mutually cooperating to dispose said hub portion in spacedrelation to the adjacent end wall surface of said conduit, an expansiblecoupling member openly communicating with said hub portion to receiveliquid under pressure therefrom, and a rigid structure carried by saidrack means above said coupling member, whereby upon flow of liquidthrough said hub portion the expansion of said coupling member againstsaid structure maintains said hub and said conduit in the said spacedrelationship at all times during flow of liquid into said hub portion.

6. In a dishwasher having a tub and rack means removably containedtherein for receiving articles to be washed, a rigid, open-ended conduitextending into said tub intermediate said rack and a wall of said tub,and means for supplying said conduit with liquid under pressure fordischarge into said tub: the improvement comprising a liquiddistribution device having a hub portion openly facing said conduit toreceive liquid therefrom, tubular members communcating with said hub andextending therefrom, said tubular members having apertures arranged toproduce reaction jets urging said hub into rotation, bearing structureon said hub portion and said conduit disposing said hub portionrotatably on said conduit in spaced relation to the adjacent end Wallsurface of said conduit While permitting said hub portion to gyraterelative to said conduit, an expansible coupling member openlycommunicating with said hub portion to receive liquid under pressuretherefrom, said coupling member having a flexible terminal portion, anda rigid structure carried by said rack means above said coupling member,whereby upon flow of liquid through said hub portion said couplingmember expands to bring the said flexible portion thereof against saidstructure to maintain said hub and said conduit in substantially thesaid spaced a relationship while permitting gyrations of said hubportion.

7. In a dishwasher having a tub and rack means removably containedtherein for receiving articles to be washed, a rigid, open-ended conduitextending into said tub intermediate said rack and a Wall of said tub,and means for supplying said conduit with liquid under pressure fordischarge into said tub: the improvement comprising a liquiddistribution device having a hub portion openly facing said conduit toreceive liquid therefrom and liquid distribution members communicatingwith said hub and extending therefrom, means for freely rotatablymounting said hub portion on said conduit intermediate said conduit andsaid rack with said hub portion in spaced relation to the adjacent endwall surface of said conduit, means for effecting rotation of said hubmember upon flow of liquid therethrough, an expansible coupling memberopenly communicating with said hub portion to receive liquid underpressure therefrom, and a rigid structure rotatably mounted within saidtub in predetermined spaced relation to said coupling member, wherebyupon flow of liquid through said hub portion said coupling memberexpands against said structure to maintain said hub and said conduit inthe said spaced relationship while permitting rotation of said hubportion.

References Cited in the file of this patent UNITED STATES PATENTS1,577,225 Granger Mar. 16, 1926 1,594,054 Fiego July 27, 1926 1,628,818Zademach May 17, 1927 1,668,582 Buckner May 8, 1928 2,500,404 DonnellyMar. 14, 1950 2,681,658 Meeker et a1. June 22, 1954 2,731,296 GrifiithJan. 17, 1956

